1. Biotic Indexing
= FUN!
(Picking for the bugs and other
critters)

2. Why?
• One-third of the data we’ll get for
determining a river’s health is biological

3. Invertebrates
• Spineless:
• Mostly Insects
• Life Cycle: Many
insects start their life
in water
• Larval or Nymph

5. Nymph vs. Larvae

6. Canary in a Coal Mine
• They are very sensitive
• Some more than others

7. How?
With respect!
– To them
– To environment
– To people after you
With Care
Get a rock------search it carefully-----grab the
critter-----put in pan------return the rock
where it came from--------get more-----
identify and tally them----- put them back

8. Careful observation and care
needed

9. There are 2 Indices
• EPT Index (Ephemeroptera, Plecoptera, Trichoptera)
A measure of the variety of insects.
---AND---
• Biotic Index
Based on sensitivity of insects to pollution